Device for shifting the position of a swiveling holder

ABSTRACT

The invention is directed to a device for switching a swivelable holder between two positions, e.g., for switching microscope objectives. The actuating element and swivelable holder are connected by two stretchable connection elements which serve to transmit the rotational movement and to fix the swivelable holder in the switching positions.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority of International Application No.PCT//EP03/01721, filed Feb. 20, 2003 and German Application No. 102 09283.4, filed Mar. 1, 2002, the complete disclosures of which are herebyincorporated by reference.

BACKGROUND OF THE INVENTION

a) Field of the Invention

The invention is directed to a device for switching a swivelable holderbetween two positions. It is applicable wherever the movement of anactuating element is used to switch a swivelable holder between twodefined positions.

b) Description of the Related Art

An application of this kind exists, for example, in the field ofmicroscope construction where, e.g., interchangeable objectives,filters, shutters, prisms or mirrors are to be placed in the beam pathselectively so as to be accurately positioned.

In this connection, it is usual to provide the swivelable holder and theactuating element with toothed wheels and to transmit the rotationalmovement of the actuating element to the swivelable holder. When theaxes of the actuating element and swivelable holder intersect,combinations of spur gears and bevel gears are preferably used.

An example for the actuation of a swivelable holder by means of toothedwheels is shown in DE PS 32 40 401. Although toothed wheel drives of thekind mentioned above can be manufactured inexpensively, per se, thesearch for cost-saving solutions continues.

OBJECT AND SUMMARY OF THE INVENTION

Accordingly, it is the primary object of the invention to provide adevice of the generic type which is simpler to produce than previouslyknown solutions.

According to the invention, this object is met in a device for switchinga swivelable holder between two positions having a rotatable actuatingelement. The swivelable holder has a stop for each position. Twostretchable connection elements are provided, each of which isarticulated at the actuating element and at the swivelable holder at adistance from the axes of rotation of the holder. The articulationpoints are located essentially opposite one another with respect to theaxes of rotation.

When the actuating element is rotated, one of the two connectionelements is stretched and accordingly exerts a torque on the swivelableholder which moves the latter out of its initial position. After thedead center is overcome, it is pressed by the connection element againstthe stop associated with the second position and accordingly occupies adefined position. The actuating element can be rotated further againstthe tension of the first connection element until the catch is reachedand the actuating element snaps in. The swivelable holder is now held inposition by the connection element which is under tension. Changing backinto the first position takes place in an analogous manner.

Now, instead of elaborate pairs of toothed wheels and bearing supportsfor them, only commercially available tension springs or cables ofelastomeric material are required for transmitting movement.

The positioning accuracy is determined only by the two stops which canbe adjustable. A high degree of accuracy for the catching of the drivingaxle is not required.

The invention can be applied when the axes of the actuating element andswivelable holder are in a parallel position and also when the axesintersect.

The invention will be described in the following for the preferred casewith intersecting axes.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings:

FIG. 1 shows a schematic top view of the preferred embodiment example;and

FIG. 2 shows a schematic side view of the preferred embodiment example.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIG. 1 shows a swivelable holder constructed as a rotating plate 1 whichis rotatable around an axle 2. The rotating plate 1 has openings 3 forreceiving objectives, not shown, which are swiveled into the beam pathin pairs, e.g., in a stereo microscope. The rotating movement of therotating plate 1 is limited by the pin 4 which is attached to therotating plate 1 and which acts against two stationary, but preferablyadjustable, stops 5, 5′. The stops can be constructed as eccentric camsfor purposes of adjustment.

The actuating element 6 comprises an axle 7 that can be provided with agripping surface and a disk 8 that is fixedly connected to the axle 7.The connection between the actuating element 6 and the rotating plate 1is produced by two tension springs 9, 10, preferably of the same length,which are so articulated at the disk 8 and rotating plate 1 at adistance from the respective axes of rotation that the axes of rotationextend approximately centric to the articulation points. The disk 8 canbe fixed by means of a spring-loaded locking piece or catch 11 in afirst groove 12.

In the side view (FIG. 2), the elements are provided with the samereference numbers as in FIG. 1. A second groove 13 is introduced intothe disk 8 and the catch 11 locks in this second groove 13 in the secondswitching position.

In order to switch to the second switching position, the catch 11 isunlocked from the groove 12 by rotating the actuating element 6 in thedirection of arrow 14. Due to the rotation of the disk 8 caused by this,spring 10 is stretched and spring 9 is relaxed. The stretched spring 10accordingly exerts a torque on the rotating plate 1, which torquerotates the rotating plate 1 until the pin 4 strikes against the secondstop 5′. The actuating element 6 is further rotated until the catch 11locks in the groove 13, so that the spring 10 is tensioned and providesthat the second position of the rotating plate fixed by the stop 5′ isreliably retained.

Switching back into the first position of the rotating plate 1 iscarried out by the actuating element 6 rotating opposite to thedirection indicated by the arrow 14, so that spring 9 is rotated andspring 10 is relaxed. As a result of the torque exerted by the spring 9on the rotating plate 1, the latter is rotated until the pin 4 strikesagainst the stop 5. By further rotation of the actuating element 6 untilthe catch 11 locks into the groove 12, the spring 9 is tensioned andsecures the position of the rotating plate 1 in the first position. Thetwo switching positions of the rotating plate 1 are therefore fixedexclusively by the stops 5, 5′. The position of the grooves 12, 13 forthe catch 11 in combination with the spring constants of the springs 9,10 only determines the retaining force of the rotating plate in theswitching positions.

This results in a very simple construction which nevertheless achieves areliable and accurate switching of the rotating plate. The realizationof the invention is not limited to the embodiment example shown herein.For example, the springs can also be articulated at the axles of therotating plate and actuating element by means of levers. The swivelableholder can also be constructed from swiveling arms instead of the diskand rotating plate shown in the embodiment example.

Similarly, the principle according to the invention can also be appliedwhen the axles extend parallel to one another.

While the foregoing description and drawings represent the presentinvention, it will be obvious to those skilled in the art that variouschanges may be made therein without departing from the true spirit andscope of the present invention.

1-7. (canceled)
 8. A device for switching a swivelable holder betweentwo positions comprising: a rotatable actuating element, said swivelableholder having a stop for each position; and two stretchable connectionelements being provided, each of which being articulated at saidactuating element and at the swivelable holder at a distance from axesof rotation of said holder, wherein the articulation points are locatedessentially opposite one another with respect to the axes of rotation.9. The device for switching a swivelable holder according to claim 1,wherein the axes of rotation of the swivelable holder and of theactuating element are directed substantially parallel to one another.10. The device for switching a swivelable holder according to claim 1,wherein the axes of rotation of the swivelable holder and of theactuating element extend substantially at an angle of 90° relative toone another.
 11. The device for switching a swivelable holder accordingto claim 1, wherein the actuating element preferably has a catch. 12.The device for switching a swivelable holder according to claim 1,wherein the two stretchable connection elements extend substantiallyparallel to one another.
 13. The device for switching a swivelableholder according to claim 1, wherein the stretchable connection elementsare constructed as springs.
 14. The device for switching a swivelableholder according to claim 1, wherein the stretchable connection elementsare constructed as elastic cables.